The goal of this clinical trial is to compare the effectiveness of two different dexamethasone treatment regimens (the DART regimen and the medium-dose tapering regimen) in reducing the incidence of Bronchopulmonary Dysplasia (BPD) or death by 36 weeks of postmenstrual age in premature infants. This study will also assess the safety of these treatments. The main questions it aims to answer are: Does the DART regimen, compared to the medium-dose tapering regimen, lower the rate of BPD or BPD-related death by 36 weeks of postmenstrual age in eligible premature infants? How do the two regimens compare in terms of short-term respiratory outcomes (like time to come off the ventilator), complications at hospital discharge, and long-term neurodevelopmental outcomes at 18-24 months of corrected age?

Researchers will compare the DART regimen group (lower cumulative dose, given over 10 days) to the medium-dose tapering regimen group (higher cumulative dose, given over 7 days) to see which one is more effective and safer.

Participants will:

Inclusion Criteria (Must meet ALL of the following)

1. Gestational age 24+0 to 29+6 weeks; requires invasive mechanical ventilation for ≥14 days after birth; within 14-28 days of age at first receive of dexamethasone.
2. FiO₂ > 40% and MAP > 8 cmH₂O (maintained for at least 24 hours prior to enrollment).
3. Parent/Legal guardian has provided signed informed consent.
4. No use of other steroid medications prior to enrollment, as explicitly stated in the inclusion criteria.

2. Exclusion Criteria (Will be excluded if they meet ANY of the following)

1. Presence of ventilator-associated pneumonia at the time of enrollment.
2. Severe congenital malformations (e.g., severe cardiac anomalies, congenital diaphragmatic hernia, etc.), or known immunodeficiency.
3. Suffering from other severe life-threatening illnesses with a short-expected survival time.
4. Parent/Legal guardian refuses to participate in the study.

This study is a multicenter, prospective, randomized, parallel-controlled clinical trial.

Study Sites: Multiple hospitals across China with high-level Neonatal Intensive Care Units (NICUs) will participate.

Randomization:

A randomization method will be used to assign participants to one of two study groups in a 1:1 ratio. Subjects will receive a unique randomization number in the order of enrollment and will be assigned to one of the following treatment groups:

• DART regimen
• Moderate-dose tapering regimen

Blinding:

Blinding will be applied for the assessment of secondary outcomes (e.g., neurodevelopmental outcomes). Evaluators will be from an independent team and will not be involved in the routine clinical care of the infants.

1. DART Regimen Group

   Cumulative dose: 0.89 mg/kg over 10 days Intravenous dexamethasone [17], administered as follows:

   • 0.075 mg/kg/dose, every 12 hours for 3 days
   • 0.05 mg/kg/dose, every 12 hours for 3 days
   • 0.025 mg/kg/dose, every 12 hours for 2 days
   • 0.01 mg/kg/dose, every 12 hours for 2 days, then discontinue

   If extubation is not successful more than or equal to two weeks after completing the treatment (FiO2 > 40% and MAP > 8 cmH2O), the DART regimen may be repeated. The number of repeated courses, reasons, and specific timing must be documented.

   (Note: According to reference [13], if the infant meets respiratory criteria again at least 72 hours after completing the initial 9-day course, a second 9-day course may be administered. If the infant meets the criteria again during the 42-day observation period, a third course may be considered.)

   Rationale for design:

   Due to the rapid physiological changes in preterm infants, early responses to interventions are often evident within short timeframes. The shorter assessment intervals aim to capture early treatment effects more sensitively and dynamically.

   Previous exploratory observations indicated that two-week intervals are feasible and safe for evaluating parameters such as weight gain and lab changes, with no significant adverse effects observed.

2. Moderate-Dose Tapering Regimen Group

Cumulative dose: 2.35 mg/kg over 7 days Intravenous dexamethasone [19], administered as follows:

• 0.5 mg/kg/d for 3 days
• 0.25 mg/kg/d for 3 days
• 0.1 mg/kg/d for 1 day

If extubation is not successful more than or equal to two weeks after completing the treatment (FiO2 > 40% and MAP > 8 cmH2O), the same regimen may be repeated. The number of repeated courses, reasons, and specific timing must be documented.

Definition of BPD Severity (based on 2019 consensus criteria):

Clinically, BPD is defined as oxygen and/or respiratory support dependency for at least 28 days or continuing until 36 weeks corrected gestational age in preterm infants born at <32 weeks gestation.

Inclusion Criteria (Must meet ALL of the following)

1. Gestational age 24+0 to 29+6 weeks; requires invasive mechanical ventilation for ≥14 days after birth; within 14-28 days of age at first receive of dexamethasone.
2. FiO₂ > 40% and MAP > 8 cmH₂O (maintained for at least 24 hours prior to enrollment).
3. Parent/Legal guardian has provided signed informed consent.
4. No use of other steroid medications prior to enrollment, as explicitly stated in the inclusion criteria.

Exclusion Criteria (Will be excluded if they meet ANY of the following)

1. Presence of ventilator-associated pneumonia at the time of enrollment.
2. Severe congenital malformations (e.g., severe cardiac anomalies, congenital diaphragmatic hernia, etc.), or known immunodeficiency.
3. Suffering from other severe life-threatening illnesses with a short-expected survival time.
4. Parent/Legal guardian refuses to participate in the study.

After the article was published